Various types of digital terminals such as a mobile phone, a navigation, a digital information display (DID), a tablet, and the like, which are currently being released, basically provide a touch interface. A technology that has currently risen as a method of increasing user experience while interacting with the touch interface is a haptic technology of providing a haptic sense. In a case of using the haptic technology, it is possible to provide a more realistic user interface by generating various types of haptic senses and providing the user with a feedback in which a sense of sight and a sense of touch are converged when the user interacts with a digital object.
A motor scheme is most general as a scheme for providing a haptic sense according to the related art. The motor scheme has been variously utilized for a mobile device due to a quick response speed, low power, and easy haptic output control. However, in a case of providing the haptic sense using the motor scheme, it is difficult to arrange modules due to a size of a haptic module and the thickness itself of a mechanism becomes thick. In particular, the related art using the motor scheme is in a structure in which vibration spreads to the overall mechanism and thus, it is difficult to provide a localized haptic sense only to a portion where a user hand touches. Accordingly, there is a difficulty in applying the related art to a navigation, a DID, a monitor, and the like, which are not portable electronic devices.
To overcome the above disadvantages, a film type haptic module technology capable of mounting a film type haptic module on a display panel has recently appeared. The film type haptic module is generally classified into a case of using transformation of a material itself using an electro active polymer material and a case of using an electrostatic force. Here, in the case of using the electro active polymer material, it is possible to configure a haptic module that is a film type, uses low power, and has a quick response speed based on a characteristic of polymer. In this instance, it is difficult to provide sufficient output only with transformation of the polymer material and thus, an additional device (mass) having a predetermined weight may also be used. Consequently, transformation of the electro active polymer activates the additional device and a user is provided with a haptic sense due to the activation of the additional device. Accordingly, in this case, an electro active polymer layer and the additional device are required to provide sufficient output.
The existing scheme using the electrostatic force is a principle of generating a haptic sense by an electrostatic force that occurs between two sheets of substrates, that is, an instantaneous attractive force and repulsive force by matching the same or different charges to each substrate in a state in which two sheets of substrates coated with a conductive material are disposed to face a conductive layer. An actuator device including two sheets of substrates as above is independently configured on or below a touch panel. In an actual application, an insulating layer inserted between substrates is also required to prevent current pass.
In the case of the aforementioned related arts, a plurality of substrates, an electrode layer, an insulating layer, and the like, need to be inserted on or below an existing touch panel in order to simultaneously provide a location recognition and a haptic feedback by a touch. However, in a case of inserting the above structure into a touch screen, there are problems, such as a decrease in product yield, an increase in cost, and degradation in light transmittance. Accordingly, it is very difficult to apply the above structure to an actual product.